An electromotor is well known as a rotation apparatus utilizing a magnetic force. For example, an AC electromotor comprises a rotor having a coil, a stator surrounding the rotor, and a plurality of electromagnets, disposed on the stator, for generating a rotating magnetic field. An electric power must be constantly supplied to the electromagnets in order to generate the rotating magnetic field and keep the rotor rotating, i.e., an external energy, or electric energy, is indispensable for the rotation of the rotor.
Under the circumstances, a magnetic rotation apparatus, which employs permanent magnets in lieu of electromagnets and can rotate a rotor only by a magnetic force of the permanent magnets, is highly desirable.
The present application proposes a magnetic rotation apparatus which comprises a pair of rotors rotatable in opposite directions in a cooperating manner, and a plurality of permanent magnets stationarily arranged at regular intervals on the peripheral portion of each rotor. One end portion of each permanent magnet of both rotors, which has the same polarity, is located radially outward of the rotors. When the two rotors are rotated in a cooperating fashion, a permanent magnet on one rotor and a corresponding permanent magnet on the other, which form a pair, approach and move away from each other periodically. In this case, the phase of rotation of the magnet on one rotor advances a little from that of the corresponding magnet on the other rotor. When the paired permanent magnets approach each other, magnetic repulsion causes one rotor to rotate. The rotation of one rotor is transmitted to the other rotor to rotate the same. In this manner, other pairs of magnets on both rotors sequentially approach each other, and magnetic repulsion occurs incessantly. As a result, the rotors continue to rotate.
In the above apparatus, in order to stop the rotation of the rotors, a brake device is required. If an ordinary brake device is mounted on the magnetic rotation apparatus, the entire structure of the apparatus becomes complex, and a driving source for the brake device must be provided separately.
The present invention has been developed in consideration of the above circumstances, and its object is to provide a magnetic rotation apparatus including a brake device for suitably stopping the rotation of rotors.